1. Field of the Invention
This invention relates to semiconductors and more particularly, but not by way of limitation, relates to capacitors, as well as systems and methods for making and using capacitors.
2. Description of the Related Art
Capacitors may be used in certain electrical devices. For example, the metal-insulator-metal (MIM) capacitor is one component that may be used in certain semiconductor devices. MIM capacitors are also found in some integrated circuits, including analog and mixed signal integrated circuits, and are one of the main components in radio frequency devices. The MIM capacitors can be used for decoupling, filtering, oscillating, and other tasks within these devices.
Semiconductor capacitors may include an electrode layer, and insulator layer, and a second electrode layer. The insulator layer may be characterized as a dielectric layer. In the field of semiconductor device fabrication, progress is commonly gauged by a reduction in the size of semiconductor components. Unfortunately, reduction in the size of a capacitor also reduces its capacitance and increases leakage current density through the electrodes. Multiple dielectric layers are used in some semiconductor capacitors to combat this problem. For example, “Capacitor of Analog Semiconductor Device Having Multi-Layer Dielectric Film and Method of Manufacturing the Same” (U.S. Pat. No. 7,407,897) discloses a capacitor with a multi-layer dielectric film that includes a first interlayer insulator on a semiconductor substrate, lower electrode on the first interlayer insulator, a lower dielectric film having a negative quadratic voltage coefficient of capacitance, a intermediate dielectric film a positive voltage coefficient of capacitance on the lower dielectric film, an upper dielectric film having a negative quadratic voltage coefficient of capacitance on the intermediate dielectric film, and an upper electrode on the upper dielectric film.